1. Technical Field
The present invention relates to recording apparatuses.
2. Related Art
Ink jet printers (hereinafter simply referred to as “printers”) that eject ink from a recording unit such as a recording head onto a paper sheet so as to record a certain image (including characters and graphics) are an example of a type of recording apparatus that ejects liquid such as ink onto a recording medium such as a paper sheet so as to perform a recording operation.
Such printers are provided with a feeding cassette containing a plurality of stacked paper sheets therein (hereinafter simply referred to as a “cassette”) and are configured to record images on the paper sheets while feeding the uppermost paper sheets one by one toward the recording unit. Accordingly, the printers include a mounting unit in which the cassette containing a plurality of stacked paper sheets therein is detachably mounted by inserting the cassette in a direction perpendicular to a stack direction of the paper sheets and a paper feeding roller that separates the paper sheets one by one and feeds out the separated paper sheets from the cassette in a mounted state in the mounting unit toward the recording unit in a sequential manner.
The printer further includes a separation slope that is disposed at the internal end face of the mounting unit in which the cassette is mounted, that is, at a position opposite the front end of the cassette in a mounted state in the mounting unit in the insertion direction. The separation slope is formed to guide the paper sheets toward the recording unit when the paper feeding roller separates the paper sheets one by one and feeds out the separated paper sheets from the cassette.
Since the cassette is mounted in the mounting unit by a user, when the cassette is inserted into the mounting unit at a rapid speed, some of the paper sheets stacked in the cassette may be urged in the insertion direction by the inertia force and may be disposed on the rising separation slope. As a consequence, the separation slope fails to separate the paper sheets one by one, thereby causing a double feeding state in which two or more paper sheets are fed together. This may cause a problem such as a paper jam.
JP-A-2000-335769 discloses a mechanism for preventing the above-mentioned problem, in which a shutter member that moves downward from a retreat position in an upper region to a control position in a lower region is provided so that the shutter member controls the movement of the end of the paper sheets downstream in the feeding direction (hereinafter referred to as a “leading edge of the paper sheets”) in the insertion direction of the cassette. The lower end of the shutter member is configured to rotate upstream in the feeding direction when the shutter member moves up from the control position in the lower region where the shutter member abuts the leading edge of the respective paper sheets to the retreat position in the upper region. With this configuration, the shutter member permits the leading edge of the respective paper sheets abutting the shutter member and to be aligned with the slope surface such that the leading edge of the paper sheet in the higher position in the stack comes to a position more downstream in the feeding direction.
However, with the configuration disclosed in JP-A-2000-335769, a space for providing a rotation mechanism and a slide mechanism for sliding the shutter member into the retreat position while rotating the shutter member is needed. In addition, a space for housing the shutter member, the rotation mechanism and the slide mechanism is also needed. Those spaces cause a problem in that the printer becomes large.
In order to solve the above problem, for example, a configuration using a control member that has a control surface to control the movement of the paper sheet in the forward direction of the insertion direction of the cassette and that rotates to turn over in the insertion direction has been proposed. That is, in this case, the movement of the paper sheet is controlled by the control surface and the momentum of the paper sheet is reduced, and then, the control of the movement of the paper sheet is released when the control surface rotates so as to retreat from the separation slope with a predetermined time delay.
With this configuration, the paper sheets are separated one by one and guided to the recording unit without being disposed on the separation slope. As a result, only a space for a rotation movement mechanism of the control member is required without having to provide a wide space for housing a shutter member, a rotation mechanism and slide mechanism into the retreat position, therefore it is possible to prevent a printer from becoming large.
During such a rotation movement of the control member, a damper member is used to cause a predetermined time delay after controlling the movement of the paper sheets. That is, since a movement member of the damper member moves with a resistance, a time delay is generated between the time when the movement of the paper sheets is controlled and the time when the control is released by the rotation movement of the control member.
In such a damper member, since the control member moves cooperatively with the moving member, the control member has a cam that comes into sliding contact with a cam face of the moving member. However, when the paper sheets strongly collide against the control surface of the control member, the moving member fails to fully support the control member and is forced to move immediately without generating a predetermined time delay for the rotation operation of the control member. That is, the control member cannot resist the impact of the paper sheets and is forced to rotate to the release position and releases the control of the movement of the paper sheets before fully controlling the movement of the paper sheets. This results in a problem in that the control member fails to fully control the movement of the paper sheets.